To the Editor:
We read with great interest the recent paper by Robson et al. (1). The authors described their experience on power Doppler assessment of perifollicular vascularity (PV) at the time of ultrasound-guided transvaginal oocyte retrieval in infertile patients who underwent in vitro fertilization (IVF) showing that this procedure is practical and reproducible, and concluding that it should be tested in larger studies in order to define its clinical value.
During the last four years we have also employed the PV evaluation in infertile patients treated with different ovulation inductors (2-4) in order to predict their reproductive success, and we agree with the authors regarding the feasibility of this procedure and its potential role for managing patients scheduled for IVF and non-IVF cycles. Moreover, we feel the need to clarify that the feasibility and the reproducibility of the procedure are strongly related to patients’ characteristics that, unfortunately, are not reported in the paper by Robson et al. (1). In fact, they decrease linearly with the number of follicles developed at time of human chorionic gonadotropin (hCG) injection or oocyte retrieval. On the other hand, the use of the PV assessment should have a clinical usefulness just in these patients in order to help the embryologist to choose the best oocyte(s) to transfer.
To this regard, our previous clinical data demonstrated that power Doppler PV assessment has no clinical utility for oocyte selection either in young (2) or in old (4) infertile patients scheduled for IVF cycles, respectively, for the high number of optimal quality oocytes obtained (from high-grade follicles) and for the impossibility of discriminating among a low number of available oocytes. However, our opinion is that the PV evaluation could have a significant value for older patients with good ovarian reserve who develop multiple follicles having variable PV and oocyte quality (4).
A point of discussion for the authors (1) was if the hCG administration changes the PV pattern. Our previous data (2), obtained in 27 patients who received recombinant FSH for inducing controlled ovarian hyperstimulation, demonstrated no difference in PV, as assessed by power Doppler, between the day of hCG injection and of oocyte retrieval. Of note, the PV assessment was recorded and then re-observed before the second evaluation, and measured using a computer analysis of image (2).
In conclusion, we think that the PV assessment is a tool with great potential, and that further studies are needed to test its clinical effectiveness in selected population of infertile patients.Stefano Palomba, MD
Angela Falbo, MD
Tiziana Russo, MD
Fuvio Zullo, MD Department of Obstetrics & Gynecology University “Magna Graecia” Catanzaro, Italy
1. Robson SJ, Barry M, Norman RJ. Power Doppler assessment of follicle vascularity at the time of oocyte retrieval in in vitro fertilization cycles. Fertil Steril 2008;90:2179-82.
2. Palomba S, Russo T, Falbo A, Orio F Jr, Manguso F, Nelaj E, et al. Clinical use of the perifollicular vascularity assessment in IVF cycles: a pilot study. Hum Reprod 2006;21:1055-61.
3. Palomba S, Orio F Jr, Falbo A, Russo T, Tolino A, Zullo F. Effects of metformin and clomiphene citrate on ovarian vascularity in patients with polycystic ovary syndrome.Fertil Steril 2006;86:1694-701.
4. Palomba S, Russo T, Orio F Jr, Falbo A, Tolino A, Zullo F. Perifollicular vascularity assessment for selecting the best oocytes for in vitro fertilization programs in older patients. Fertil Steril 2008;90:1305-9.
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2009.01.157
The Authors Respond:
We would concur with the comments of Doctor Palombo and colleagues that measurement of perifollicular vascularity is a technique with potential to improve selection of embryos for transfer in IVF cycles. As previously stated, we had been frustrated with the technical difficulties encountered in trying to ‘map’ follicular vascularity in advance of oocyte retrieval. Our pilot study aimed to evaluate the feasibility of undertaking vasularity assessment at the time of oocyte retrieval, to reduce the need for repeated patient ultrasound examinations and to improve accuracy. We felt that these objectives were achieved in the small series. We agree completely that the time is ripe for further prospective large scale studies of the utility of this technique in IVF.Stephen J. Robson, MPHa
Michael Barry, BScb
Robert J. Norman, MDb,c
aDepartment of Obstetrics and Gynaecology
Australian National University
Canberra Hospital, Canberra
cResearch Centre for Reproductive Health
University of Adelaide
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2009.01.155